Arm rest adjuster for chairs



g- 9, 1955 M. D. RECHLER 2,715,065

ARM REST ADJUSTER FOR CHAIRS Filed Feb. 10. 1955 2 Sheets-Sheet l ATTORNEY 9, 1955 M. D. RECHLER 2,715,035

ARM REST ADJUSTER FOR CHAIRS Filed Feb. 10, 1953 2 Sheets-Sheet 2 ATTORNEY United States Patent Ofiice 2,715,035 Patented Aug. 9, 1955 ARM REST ADJUSTER non cHAiRs Morton D. Rechler, New York, N. Y., assignor to Rexart Metal Industries, Inc., New York, N. Y., a corporation of New York Application February 10, 1953, Serial No. 336,081

2 Claims. (Cl. 287-44) This invention relates to rotatable joints, and particularly to a type which is suitable for incorporation in a chair to effect shifting of a back rest to different positions.

One object of the invention is to provide adjusting means in association with the arm rests and leg structure which will be easy to adjust to different positions to change the inclination of the back rest while occupying the chair.

Another object is to provide a construction involving the use of simple light weight parts which are easy to manufacture and assemble, and wherein suflicient lateral stability is obtained in this light structure to insure proper rigidity.

The mechanism is designed for installation on various kinds of chairs for adjusting a back rest, and is adapted to fold with the parts of a folding chair to occupy a minimum of space.

Other objects and advantages will appear as the description proceeds, reference being made to the accompanying drawing in which:

Fig. l is a perspective view showing my improved adjusting means incorporated in a folding chair.

Fig. 2 is a similar view showing the mechanism adjusted to bring the back rest into an intermediate position of inclination.

Fig. 3 shows the back rest in a fully inclined position.

Fig. 4 is an enlarged side elevation of one of the adjusting devices and associated parts of a chair.

Fig. 5 is a vertical section on line 55 of Fig. 4.

Fig. 6 illustrates a linkage element.

In Figs. 1, 2 and 3 there is shown a chair framework indicated generally by the numeral 10, and consisting of a seat frame 11, front legs 12, rear legs 13, back rest or frame 14, arm rests 15, tie rods 16, and a cross rod 17 upon which the rear legs 13 and back rest 14 are pivoted. This chair is illustrated as an example of a suitable type in which to incorporate the adjusting means of this invention and to provide a folding framework wherein all of the parts cooperate in folding to flat form to take small space for carrying. The mechanism may be applied to any chair structure having a back rest pivoted to be moved to different angles of inclination.

In Figs. 4 and 5 which are life size views of the adjusting mechanism, the numeral indicates an inverted U-shaped bracket having side plates 21 and 22 and a base 23 by means of which it is attached as by screws 24 to the under face 25 of arm rest 15. The plates 21, 22 are provided with opposite openings 26 for the passage of a bolt 27 which rides in a lengthwise slot 28 in each of two links 29 having inner ends 29a located between the side plates and spaced apart by sleeve 30 so that while the links 29 may swing freely about the bolt 27 they are at the same time close enough to the side plates to be stabilized thereby against lateral sway. The other ends 31 of links 29 have alined openings 32 for a bolt 33 which also passes through transverse openings 34 in the upper end 35 of leg 12 and through an opening its other angles of inclination.

36 in tie rod 16, giving the links pivotal mounting atop the leg 12.

Side plates 21 and 22 are provided with rearnotches 37, intermediate abutments 38, andfront abutmerits 39 adapted to be selectively engagedby the extending ends 4%) of a shouldered pin 41, the ends being passed through opposite holes 42 of links 29 and providing detents which are spaced radially a proper distance from the slots 28 so that the pin will follow the cam edges or faces 43 and 44 as the links swing around bolt 27 making certain the pin will pick up the next position. The sleeve 30 and the shouldered pin 41 both act to space the links 29 apart and reinforce the joint.

In Figs. 2 and 4 the pin 41is shown with its ends 40 in engagement with intermediate abutments 38 giving the back rest 14 a mediuminclination. In moving from this to the fully inclined position of Fig. 3 the pin ends 40 which have been previously disengaged from abutments 38 ride forwardly on camfaces 43 and engage abutments 39. Now if it is desired to shift to the upright position of Fig. 1, the arm rest 15 is pushed forward, whereupon the pin ends 40 ride around on cam faces 43, 44 dropping off to position 45 against stop edges 46 after which the ends slide into notches 37 from a slight back pull on arm rest 15. All of these changes are easily made and with a minimum of effort by the occupant. It is to be noted that the slot 28 permits disengagement of ends 40 from abutments 38 by an upward pull on arm rest 15, and also allows sufficient lengthwise shifting of links 29 to accommodate the upright and fully inclined positions of the back rest. This mechanism is shown in Figs. 1, 2, 3 as embodied in a folding chair wherein the seat frame, back frame and rear legs fold about cross rod 17 while the front legs 12 frame is moved to folded position under the seat frame by the action of tie rods 16. The folding is initiated by moving the seat frame toward the back rest, while unfolding is accomplished by the reverse. During the folding the pins 41 are moved by the links 29 from any forward positions to the rear notch location where they remain while the chair is folded. When the chair is being opened the pin ends 40 drop into notches 37 making the chair ready for use in its upright position from which it may be adjusted to bring the back rest to When the chair is in opened position the extending ends of cross rod 17 rest upon the upper edges of tie rods 16. The parts of this adjusting mechanism are produced by simple stamping and bending operations and are easily installed beneath the two arm rests by the screws 24 and the bolts 33.

In the present example the cam faces 43 between abutments 38 and 39 describe two arcuate edges which are uniformly distant from the pivot bolt 27 throughout the length of the edges, whereas cam faces 44 describe two spiral edges which increase in radial distance from the bolt toward the rear notches 37. These distances are indicated in Fig. 4 by the radial lines 47 and 48 respectively. Since the links 29 are preferably of light metal they may be provided with turned portions 29b or otherwise reenforced to strengthen the structure of the joint and prevent lateral sway. In operation, when the bracket is pushed to the forward position and the pin ends 40 ride off of the spiral edges 44 and into notches 37 the bracket is held against shifting until it is desired to make the other adjustments.

I claim:

1. A rotatable joint for adjusting a movable element forwardly or rearwardly with respect to a stationary element, comprising a U-shaped bracket having oppositely disposed side plates provided with a base attached to said movable element, a cross bolt between the side plates, a pair of links having upper ends provided with slots through which the cross bolt passes, said links having lower ends pivoted to said stationary element,

said plates having lower edges provided with front abutments, intermediate abutments, and rear notches, there being a pair of arcuate cam edges formed on the lower edges of the plates between the front and intermediate abutments, and a second pair of cam edges formed on said lower edges between the intermediate abutments and the rear notches, said first named cam edges being radially equidistant from the cross bolt throughout the length of said camedges, said second pair of cam edges being spiral edges which constantly recede from the cross bolt toward the rear notches, apin bridging said links and having pin ends adapted, to follow the cam edges and selectively engage the abutments and notches therein, said abutments being adapted to engage the pin ends and prevent rearward shifting of the bracket, said in ends allowing said abutments to move freely away therefrom upon forward shifting of the bracket, said side plates having stop edges merging with said rear notches and against which said pin ends engage to limit the forward shift of the bracket, said pin ends being adapted to slide along said stop edges and into engagement with said rear notches, said slots being lengthwise of said links and permltting the bracket to be moved relative to said pin ends.

2. A rotatable joint according to claim 1, wherein said links are spaced apart at their slotted ends by a sleeve surrounding said cross bolt, and said pin is provided with shoulders which engage opposite inner faces of said links, there being only slight clearances between said links and said side plates of the bracket.

Refer-eases Cited in the file of this patent UNITED STATES PATENTS 695,951 Seymour-e Mar. 25, 1902 1,847,398 Hurych Mar. 1, 1932 1,938,507 Wilson Dec. 5, 1933 2,361,853 Lundquist Oct. 31, 1944 2,401,999 Wolfe June 11, 1946 2,630,162 Bechler Mar. 3, 1953 2,634,542 Bode Apr. 14, 1953 2,638,970 Harber May 19, 1953 FOREIGN PATENTS 838,219 France Nov. 28, 1938 

